OFFSET
0,1
FORMULA
Equals 2*(1 - cos(1)) = 2 * A371936.
From Hugo Pfoertner, Apr 26 2024: (Start)
Equals A243596/Pi.
Equals A272795^2. (End)
EXAMPLE
0.91939538826372056519812678511404679253...
MATHEMATICA
s = N[Sum[(-1)^k/((k + 1) (2 k + 1)!), {k, 0, Infinity}], 120]
First[RealDigits[s]]
CROSSREFS
KEYWORD
nonn,cons
AUTHOR
Clark Kimberling, Apr 24 2024
STATUS
approved